Progression to multifactorial diseases is determined jointly by genes and environment. A valid approach for the prediction and prevention of such diseases might be to define at birth, or at an early age, the population at increased genetic risk by analysing the risk genes or risk alleles, the subsequent follow-up of those at risk, and the appropriate implementation of preventive measures at optimum time, if available. The feasibility and acceptance of population-wide genetic tests aimed at an early recognition of the risk of common multifactorial diseases with clinical presentation later in life is not known.The Type I Diabetes Prediction and Prevention project (DIPP) is an effort to predict and search for means to delay or prevent the disease in a large population-based cohort of children in Finland. The case of Type I diabetes is probably a useful model for the prediction and prevention of chronic, multifactorial Diabetologia (2001) AbstractAims/hypothesis. Population-wide genetic screening of susceptibility to multifactorial diseases will become relevant as knowledge of the pathogenesis of these diseases increases and preventive interventions are identified. Methods. Feasibility and acceptance of neonatal genetic screening for Type I (insulin-dependent) diabetes mellitus susceptibility and adherence of the atrisk children to frequent autoantibody follow-up were studied. Screening was offered to all families. The infants with HLA-DQB1 genotypes *02/*0302 and *0302/x (x¹*02, *0301, *0602) were invited to autoantibody follow-up. The children who developed signs of b-cell autoimmunity were invited to a separate prevention trial. Results. The parents of 31 526 babies born between November 1994 and April 1999 (94.4 % of those eligible) agreed to genetic screening. We found that 4651 infants (14.8 %) had increased genetic risk (2.5 to 15 times that of the general population) for Type I (insulin-dependent) diabetes mellitus, and 80 % of them joined the autoantibody surveillance. At the age of 1, 2, 3 and 4 years, 74, 69, 68 and 76 % of the at-risk children, respectively, attended the follow-up. A total of 17 of the 22 children (77 %) who were born during the study period and have developed diabetes carry the risk genotypes we currently use for screening. Conclusions/interpretation. Population-based screening of genetic susceptibility for Type I diabetes, linked with a possibility to participate later in a prevention trial, is highly accepted in Finland and identifies about 75 % of those developing diabetes at an early age. Families adhere well to the frequent measurement of signs of b-cell autoimmunity in the children at-risk. [Diabetologia (2001) 44: 290±297]

Previous studies suggest that enterovirus infections may initiate and accelerate ␤-cell damage years before the clinical manifestation of type 1 diabetes. We have now analyzed the role of enterovirus infections in the initiation of autoimmunity in children who have tested positive for diabetes-associated autoantibodies in a prospective study starting at birth (the Finnish Diabetes Prediction and Prevention Study). The frequency of enterovirus infections was studied using both serology and testing for the presence of enterovirus RNA in the sera of 21 children who developed and retained autoantibodies and in 104 control subjects chosen from the same study cohort and matched for the time of birth, sex, and HLA alleles determining genetic diabetes susceptibility. Sample intervals were taken as basic units of follow-up, to which the observed number of infections was adjusted. Enterovirus infections were detected in 26% of sample intervals in the case subjects and in 18% of the sample intervals in the control children (P = 0.03). A temporal relationship between enterovirus infections and the induction of autoimmunity was found; enterovirus infections were detected in 57% of the case subjects during a 6-month follow-up period preceding the first appearance of autoantibodies compared with 31% of the matched control children in the same agegroup (odds ratio 3.7, 95% CI 1.2-11.4). The frequency of adenovirus infections did not differ between the patient and control groups. Our data imply that enterovirus infections are associated with the development of ␤-cell autoimmunity and provide evidence for the role of enteroviruses in the initiation of ␤-cell destruction. Diabetes 49:1314-1318, 2000 T he etiology of type 1 diabetes comprises both genetic and environmental components. Enterovirus infections have long been suspected as potential environmental factors playing a role in the pathogenesis of type 1 diabetes (1,2). Recent prospective studies, based on enterovirus serology (3-5) and detection of enterovirus RNA in sera of prediabetic children (6), suggest that enterovirus infections may initiate and accelerate the ␤-cell-damaging process years before the clinical manifestation of type 1 diabetes. Enterovirus RNA has also been detected more frequently in patients with newly diagnosed type 1 diabetes than in healthy control subjects (7-9).Clear signs of ␤-cell damage often appear months or years before the manifestation of clinical diabetes (10), suggesting that prospective studies starting before the appearance of autoantibodies may be helpful in studying the etiology of the disease. In addition, early recognition of the individuals with ongoing ␤-cell damage may make it possibile to delay or halt ␤-cell destruction. The Finnish Diabetes Prediction and Prevention (DIPP) Study is a prospective population-based birth-cohort study in which Finnish children with increased genetic risk for type 1 diabetes are studied for the appearance of diabetes-associated autoantibodies at 3-to 12-month intervals from birth. We have now stud...

Insulin autoantibodies (IAAs) often appear as the first sign of islet cell autoimmunity in prediabetic children. Because cow's milk contains bovine insulin, we followed the development of insulin-binding antibodies in children fed with cow's milk formula. Bovine insulin- and human insulin-binding antibodies by enzyme immunoassay and IAA by radioimmunoassay were analyzed in 200 infants carrying HLA-DQB1*0302 but no protective alleles who participated in a Finnish population-based birth-cohort study. Based on the prospectively registered information, the first 100 infants enrolled in the study who were exposed to cow's milk formula before age 12 weeks and the first 100 infants enrolled in the study who were exclusively breast-fed for longer than their first 12 weeks of life were selected for the present study. Also, 11 children from the birth cohort who developed at least two diabetes-associated autoantibodies, 98 children with newly diagnosed type 1 diabetes, and 92 healthy children were studied. We found that the amount of IgG-antibodies binding to bovine insulin was higher at age 3 months in infants who were exposed to cow's milk formula than in infants who were exclusively breast-fed at that age (median 0.521 vs. 0.190; P < 0.0001). The antibodies binding to bovine insulin cross-reacted with human insulin. None of these infants tested positive for IAA. The levels of bovine insulin-binding antibodies declined in both groups at ages 12 and 18 months, whereas in the 11 children with at least two diabetes-associated autoantibodies the levels increased during the follow-up period (P < 0.0001). IgG antibodies correlated with IgG2 antibodies binding to bovine insulin (r = 0.43, P = 0.004) and IAA (r = 0.27, P = 0.02) in diabetic children, but not in healthy children. Cow's milk feeding is an environmental trigger of immunity to insulin in infancy that may explain the epidemiological link between the risk of type 1 diabetes and early exposure to cow's milk formulas. This immune response to insulin may later be diverted into autoaggressive immunity against beta-cells in some individuals, as indicated by our findings in children with diabetes-associated autoantibodies.

Northern hybridization of total RNA isolated from adult human sciatic nerve demonstrated a readily detectable hybridization signal for glucose transporter 1 (GLUT 1) mRNA. Western blot analysis demonstrated that GLUT 1 proteins extracted from adult human and from mature rat sciatic nerves had different electrophoretical mobilities. The migration positions of human and rat GLUT 1 proteins corresponded to 60-70 kDa and 55-60 kDa, respectively, as estimated by markers with known molecular masses. Indirect immunofluorescence staining localized GLUT 1 to the perineurium in the adult human sciatic nerve. Only a few endoneurial capillaries of human adult nerve stained positively for GLUT 1, which was in contrast to rat peripheral nerve where most endoneurial capillaries were positive for GLUT 1. In developing human nerves, the staining pattern for GLUT 1 was markedly different from that of the adult nerves: at 14 weeks, the perineurial cells were entirely negative for GLUT 1. Between 22 and 26 weeks of gestation, the staining reaction for GLUT 1 in the perineurium became markedly more prominent, and by 35 weeks the intense perineurial staining resembled that observed in the adult human nerves. In contrast to adult nerves, both endo- and epineurial blood vessels stained intensely for GLUT 1 in the fetal samples. Thus, the immunoreactivity for GLUT 1 in the perineurium seems to increase concomitant with the maturation of barrier properties of perineurium, whereas the transient expression of GLUT 1 in the vasculature of developing nerve may have a specific role in the proliferating endothelial cells.

The expression of type I, III and VI collagens was studied in nine normal and two hypertrophic scars using slot-blot and in situ hybridization techniques. Slot-blot hybridization indicated that the steady-state levels of pro alpha 1(I) and pro alpha 1(III) collagen chain mRNAs were moderately elevated in two of the nine normal scars, whereas the two hypertrophic scars analysed displayed markedly elevated mRNA levels when compared with normal skin. The mRNA levels of alpha 2(VI) collagen chain were only slightly elevated in both types of scars studied. In situ hybridization was most informative when applied to hypertrophic scars. These lesions were characterized by the presence of intense hybridization signals for type I and III collagen mRNAs, and a moderate signal for type VI collagen mRNA, in nodules which were located in the upper dermis on each side of the original wound. This may explain, in part, why hypertrophic scars rise above the level of the surrounding skin. The results of the present study are in marked contrast to our previous findings on collagen gene expression in keloids and neurofibromas, in which the steady-state levels of type VI and I collagen mRNAs in particular were shown to be elevated. Thus, our results emphasize that distinct molecular mechanisms are operative in the development of clinically different dermal fibrotic conditions, such as normal and hypertrophic scars, keloids and neurofibromas.